Mobile devices such as smartphones have replaced Personal Computers
(PCs) to become the primary computing devices for many users due to the rapid
advance of mobile computing technology and wireless networks. However, smartphones have limited capabilities
that can be effectively mitigated through the use of cloud computing. This
combination of mobile computing, cloud computing and wireless networks, has
given rise to a new paradigm: Mobile Cloud Computing (MCC).
Cloud Computing integrates mobile computing and cloud computing aiming to
extend mobile devices capabilities. This brings great research and business
opportunity for applications developers, mobile networks operators (MNOs),
cloud service providers (CSPs) and smartphones manufacturers.
Unfortunately, being in a very nascent
stage, mobile cloud computing has some privacy and security issues which deter
the users from adopting this technology. This paper addresses the security and
privacy challenges in mobile cloud computing with a special focus on enhancing
the end-user cybersecurity awareness. Our approach is as follows; we will first
give a succinct overview of mobile cloud computing, then present the security
and privacy requirements for mobile cloud computing, outline the security and
privacy threats for each component of this technology and, finally, make
suggestions to mitigate these vulnerabilities. In addition, we will provide a
cybersecurity checklist for mobile cloud users in order to enhance their
cybersecurity awareness through self-assessment as well as initiate some
guidance for applications developers, MNOs and CSPs.
Keywords: mobile cloud
computing, cloud computing, wireless networks, security and privacy, mobile
are becoming an essential part of human life as the most effective and
convenient communication tools. Users now prefer smartphones compared to the
traditional cell phones and personal computers. As per the Mobility Report of November,
2015 from Ericsson, by 2021, the number of smartphones users will reach 6.4
The rapid expansion of mobile computing becomes a powerful trend in the
development of Information Technology (IT) in general. However, the users of
mobile devices face many challenges in their storage and processing
capabilities. The limited resources significantly impede the improvement of
quality of services. Nevertheless, these limited capabilities are mitigated by
integrating mobile computing into cloud computing and hence a new paradigm of
computing called mobile cloud computing (MCC) emerges.
Cloud Computing (MCC) combines cloud computing, mobile computing and wireless
networks to bring rich computational resources to mobile users. The ultimate
goal of Mobile Cloud Computing is to enrich mobile users’ experience. Mobile
Cloud Computing provides also business opportunities for mobile network
operators as well as cloud providers.
mobile cloud computing suffers from several security and privacy challenges
that deter mobile users from effectively adopting this new and interesting
technology. This paper addresses the security and privacy challenges in mobile
cloud computing with a special focus on mobile users’ cybersecurity awareness.
The remainder of this paper is organized as follows: section II provides a
brief overview of MCC; section III considers the security and privacy
requirements in mobile cloud computing; section IV details the security and
privacy threats in mobile cloud computing for mobile users and suggest some
solutions to mitigate these issues and finally propose a security and privacy
checklist for mobile users and section V concludes the paper.
of Mobile Cloud Computing (MCC)
term “mobile cloud computing” was introduced in 2009 after the concept of
“cloud computing” had been launched in mid-2007. The Mobile Cloud Computing
Forum defines MCC as follows: “Mobile Cloud Computing at its simplest refers to
an infrastructure where both the data storage and the data processing happen
outside of the mobile device. Mobile cloud applications move the computing
power and data storage away from mobile phones and into the cloud, bringing
applications and mobile computing to not just smartphone users but a much
broader range of mobile subscribers”. To simplify we have this expression:
mobile devices + wireless networks + cloud computing
This MCC architecture shows that
mobile devices are connected to the mobile networks via base stations (e.g.,
base transceiver station (BTS), access point, or satellite) that establish and
control the connections (air interface) and functional interfaces between the
networks and mobile devices. Users have access to internet through mobile
networks and then benefit from the wide range of advantages offered by the
cloud (storage, processing servers, and virtualization)
Security and privacy requirements for MCC
The security and privacy
requirements for MCC may be categorized in the following way:
Confidentiality: In MCC, confidentiality is a
fundamental requirement that refers to keep mobile users’ data secret either in
transit or at rest. Users do not want their personal data use or access by
Integrity: In MCC, the data storage and
processing reside on the service provider’s end. Here, the integrity needs to
ensure the accuracy and consistency of users’ data. In other words, the
integrity prevents data tampering by any unauthorized users or systems.
Availability: For MCC, the availability
ensures that all services (Mobile networks and cloud) remain constantly
available for users. Ensuring availability includes preventing different kinds
of availability attacks, which may delay, alter or interrupt the availability
privacy threats to mobile cloud computing
and privacy in MCC are intrinsically linked since security vulnerabilities in
the mobile cloud computing paradigm will surely lead to a privacy breach. Security and privacy risks in mobile cloud
computing are inherited from cloud computing threats. Moreover mobile cloud
computing users are exposed to additional threats related to mobile devices and
mobile networks. In this section, we will present the threats to each component
of the mobile cloud computing paradigm: mobile devices, mobile networks and
today’s “always-stay-connected” world, smartphones are used for wider range of
activities such as banking, storing sensitive and valuable data. This extended
range of functionalities leads to new security threats.
run programs and store sensitive and valuable data; thus these devices are
targeted by adversaries who want to steal them in order to access sensitive
data, e.g., personal messages in online social networking application, access
the contacts list and get the smartphone itself as a valuable device. Further,
the loss of mobile devices may lead to data loss and breach of personal data
for their users and for companies as well. For instance, McAfee reports that
“Four in 10 organizations have had mobile devices lost or stolen and half of
lost/stolen devices contained business critical data”. Therefore physical
threats to mobile devices should be taken very seriously.
Malicious Software (Malware) always operates
in a way that is unknown to the user. By this means the malware gets the
illegal access to the personal information and can even lead to certain actions
without user’s interaction. Because of this, the user of the mobile terminal
could suffer from many risks such as information leakage. This illegal software
installed not by the user is used for all attacks coming from the outside
taking advantage of the vulnerabilities in smartphone’s system. The current
platforms ask users to make the decision about access. For example, iOS asks
users to give minimum permissions to the application at the installation time,
and later it asks whether an application may access other feature such as
location, and Android asks them to grant all the permissions before at the
installation time. Unfortunately, such permission-granting create some critical
threats to mobile users. The majority of these permissions is often ignored or
not understood by users and permission prompts are disruptive to the user’s
experience. As a consequence users unintentionally grant applications more
permissions than necessary and become vulnerable to applications that use the
permissions in malicious or questionable ways (i.e., secretly sending SMS
messages or leaking location information). The major ones of malware are
Trojans, Worms, Virus and Spyware.
Mobile applications vulnerabilities
applications installed on the user’s mobile device are third party
applications. These applications if they are not checked and patched regularly
could be vulnerable to malicious attacks such us code injections, which in turn
could lead to sensitive data leakage and even cause more damage to mobile
users. Moreover, security teams for both Google and Apple have been quietly
removing an undisclosed but increasing number of applications from their
stores, but they haven’t revealed a list of the removed applications or offered
any reason for their removal.
the aforementioned security issues in the mobile terminal, mobile users may be
contributing to other security issues. First of all, there is the lack of
security awareness and good security hygiene from the mobile users. For
instance, they could install unlicensed applications on their smartphones
without a prior assessment of the risks these applications could pose to the
valuable information stored on their devices.
network-based security threats usually target the Radio Access Network (RAN)
which is the interface between mobile devices and the cloud. This interface is
generally composed of Radio Base station (RBS) and Base Station Controller
(BSC) in the case of 2G networks, or NodeB/eNodeB in the case of 3G/4G mobile
networks for example. This may also refer to traditional Wi-Fi. Major Attacks
in this category include Wi-Fi sniffing, Denial of Service (DoS) attacks,
man-in-the-middle attack, and Distributed Denial of Service using compromised
mobile devices (Botnets).
to the cloud can be grouped regarding the impact they have on Confidentiality,
Integrity and Availability (CIA triad) of users data. The cloud platform is
susceptible to being attacked because of its high concentration of information
resources of users. First of all, major threats to confidentiality are achieved
by insiders and external attackers. The ultimate goal of the malicious attacker
is to steal valuable information or sabotage service. These attacks perhaps
come from malicious outside, legal cloud computing user, or inside staff of the
cloud computing operators. Second, data integrity in the cloud is an imperative
because it is frequently targeted by malicious attackers. For instance, the
implementation of poor access control procedures creates risks to data
integrity since any individual who can manage to break into the system can
tamper with the data or even worst delete the data. Third, Availability is
really vital given how dependent on users have become to cloud services. This
tenet is also targeted by attackers who are seeking to interrupt the service to
users. For example, Distributed Denial of Service (DDoS) and Denial of Service
(DoS) attacks will destroy the platform availability and close the service of
the cloud to legitimate cloud users. When users deliver all their data to the
cloud service providers without selecting the expensive backup and disaster
recovery service, they will have to cope with the risks of the data loss.
Further, the fact that cloud service providers store users data all over the
world and that users do not know exactly where their data is located poses
serious concerns regarding privacy.
The outlined threats to mobile devices especially smartphones will
negatively impact mobile users if they are not addressed seriously. First of
all, users need to be educated about security, not at the security experts
level but at least they should get the basics. They should never leave their
devices unattended. However, devices can be lost, misplaced or stolen so users
should activate lock screen and protect their phones with strong passwords such
as 10+ characters passwords with uppercase, lowercase letters, numbers and
special characters. Further, they should use biometrics authentication on their
devices. Second, users should install only applications available on stores
like App store and Play store; they should be careful about the permissions
they will grant to the applications as well as grant only minimum permissions
to the applications in order to ensure their security and protect their
privacy; it is vital for users to do some research before installing any
application on their phone. Additionally, they should always update their
applications and uninstall the ones that they don’t use anymore. Third, they
should install anti-malware on their phones and keep them up to date. Beware
also of phishing attacks and do not trust spam emails, link from an
advertisers, messages from friend’s social account that could probably be
hacked etc., because by clicking on a link it will redirect you to an infected
website. Thus it is very important to not click on short, suspicious links for
which you did not request. Attackers can use phishing techniques to steal your
money, your identity and open credit card accounts in your name and much more.
Even the strongest antivirus will not protect you from phishing and all
malicious software. They should be sure that they are connected only to secure
wireless connection, which means to not use free or public Wi-Fi, especially
when they are accessing and/or transmitting sensitive data because information
sent via public networks can be easily accessed by attackers since they are
sent in plain text.
threats to mobile networks can be mitigated by engaging mobile networks
operators to enhance the security of their networks. However, as this paper is
mainly focuses on the end-users, therefore the suggested solutions are to help
them prevent some attacks mentioned previously. The mobile users should
maintain a good security hygiene of their devices; this security hygiene starts
by keeping their operating systems and applications up to date and by being
cautious and skeptical regarding applications and links suspicious or not that
they receive on their devices, that will prevent some attacks such as
Distributed Denial of Service (DDoS) on mobile networks using compromised
mobile devices to launch botnets attacks. For threats such as man-in-the-middle
attacks, eavesdropping and Wi-Fi-sniffing, the suggested mitigations in the
literature advise the implementation of encryption to the air interface,
authentication and digital signatures by the mobile networks operators in order
to ensure the privacy and security of the mobile users. Additionally, for
Denial of service Attacks it is required
that the mobile networks operators strictly apply the security best
practices such as patches installation, vulnerability scanning, intrusion
detection and prevention systems, authentication etc. Finally, with the
upcoming 5G (5th Generation of mobile networks), some researchers are
investigating the C-RAN and chances are that it will both enhance the
end-to-end security and quality of service (QoS) in mobile networks thus
impacting the mobile cloud computing users.
mobile networks operators, cloud service providers (CSP) have to implement the
security best practices in order to ensure the confidentiality, integrity, and
the availability of the mobile users’ data. These best practices include
keeping systems patched, implementing prevention and detection techniques to
mitigate DoS attacks, also the implementation of strong authentication
mechanisms incorporating multi-factor authentication (MFA) to avoid some
malicious activities from intruders. The users data should be encrypted at
rest, in process and in transit to ensure both the integrity and the
confidentiality of the data. Moreover, cloud services providers should clearly
inform the mobile users concerning the exact location(s) of their data as well
as the mechanisms put in place to protect them. Mobile users for their part,
should always maintain a good cybersecurity hygiene i.e. install patches of
firmware and applications. Regarding security savvy end-users, there is a data
integrity mechanism called the Merkle Tree, which they could use to verify the
integrity of the data they stored in the cloud.
privacy checklist for mobile cloud computing users
section will provide a security and privacy checklist for mobile cloud users.
Our expectation is that based on this checklist mobile users would instill
mobile networks operators, cloud service providers and also applications
developers to provide a sort of
minimum accepted service level based on
users’ security and privacy requirements. This checklist also responds to the
security and privacy requirements in mobile cloud computing: Confidentiality,
Integrity, and Availability described in section III.
think that this checklist would have a great impact on the way things are
approached in the realm of mobile cloud computing because it will develop
users’ cybersecurity awareness. Obviously, this list of questions is not
exhaustive; it is based on some telecommunications engineers and cybersecurity
experts’ experiences on the matter.
1-Is your smartphone access
protected with 10+ characters password and biometrics?
2-Do you share your passwords
3- Is your smartphone
firmware up to date?
4- Are your mobile
applications up to date?
5- Do you have anti-malware
software on your smartphone?
6- Do you use
2-factor/Multi-factor authentication for your applications dealing with
sensitive data (i.e. email, banking etc.)
7- Do you install licensed
applications and download them from trusted sources?
8- Do you verify and
understand the permissions asked by the applications before granting them?
9- Are your location based
services only activated while using General Positioning System (GPS)
10- Do you read the
application description or research information on the application before
11- Are your messages
transmitted through the Air interface protected by the use of encryption?
12- Do you use only secure
trusted wireless networks to access internet?
13-Do your service provider
maintain a very good coverage and availability even in bad weathers (storm,
14- Is your Cloud service
provider certified ISO 27001/27002/27018?
15- Do you know the exact location(s)
where your cloud service provider stores your data?
16- Are integrity
verification mechanisms such as Merkle Tree implemented for the user to
verify data integrity?
17- Is the data encrypted at
rest, in process and in transit?
18- Is a Disaster
recovery/Business continuity plan set up to ensure availability in the case
of natural disasters or man-made sabotages?
19- Do you have a cloud
the cloud service provider?
Regarding the checklist response analysis, it is
important to have “Yes” on each question to ensure a good level of privacy and
security (Green light). In our analysis, in those cases where the
respondent replies with “No” or “Don’t know”; he/she should clearly be cautious and skeptical, and review if there is
alternative features that covers this aspect of the service. However, we determine that for users to enjoy mobile
cloud computing services with security and privacy, none of the questions
addressing the following aspects should be marked “No”.
(2) Firmware and applications updates.
(3) Encryption of users data (transit/at rest)
(4) Data integrity verification mechanisms
one “No” will bring users to the “Red Light” meaning that their security
and privacy is at great risk.
Privacy and Security at great risk
Cloud computing is a very interesting technology that has changed the way users
behave; they don’t need to have traditional Personal Computers (PCs) to perform
multiple activities such as online banking, storing videos and photos etc.
However, privacy and security constitute a challenge for mobile users because
they would like to benefit from advantages offered by mobile cloud computing
while preserving the confidentiality, integrity and availability of their data.
paper outlines the security and privacy requirements of mobile cloud computing.
It also provides a cybersecurity checklist for mobile users. This checklist is
for mobile users’ self-assessment before opting for mobile cloud computing
services. Additionally, this checklist will enhance mobile users’ cybersecurity
awareness and foster the establishment of thresholds regarding users’ privacy
and security to be met by mobile networks operators, cloud service providers
and applications developers, which hopefully would make a more privacy and
security oriented technology.
study could be extended to other mobile devices such as medical devices that
are really sensitive to confidentiality and integrity since when we talk about
health accuracy and consistency are crucial because a simple modification of
health data can cause people death.